MONTREAL - How is it that Olympians make what they do look so easy? Is it because of all the hard work they’ve put in getting their body perfectly honed for one specific competition? Or, do the best of the best have something that the rest of us don’t?

According to Dilson Rassier, a muscle physiology expert and associate professor in the department of kinesiology and physical education at McGill University, most Olympians have their parents to thank for their success. To be the best in the world, you need world-class muscles and those aren’t developed just in the gym. Olympians are blessed with good genetics.

Muscles have several distinct fibre types, but for simplicity it’s best to classify them in one of three groups; fast, medium and slow twitch. Fast-twitch muscles contract and fatigue quickly. They’re used primarily for short-duration, highly explosive movements like sprinting, throwing and jumping. Sports like weightlifting, golf and tennis are also dependent on fast-twitch fibres.

Slow-twitch fibres are slow to contract and fatigue. They’re in demand during endurance sports like marathon running, triathlon, distance cycling, paddling and swimming.

In between the two are fibres that contract faster than slow twitch and don’t fatigue as quickly as fast twitch. These fibres are used primarily during middle distance events.

And while all muscles contain a combination of all three of these fibre types, some have a higher predominance of one or the other. It’s here where muscle physiologists can tell whether an athlete has what it takes to stand on the podium. Sprinters need a greater than average number of fast-twitch fibres to compete at the elite level, while endurance athletes need an abundance of slow-twitch fibres.

But that’s not the only difference. Rassier says elite athletes show distinct differences at the molecular level, where the cells show an even greater propensity for speed or endurance.

The question is, are those born without the optimum combination of muscle fibres still able to achieve Olympic glory? Rassier doesn’t think so. Training and dedication are important, but given that most of the top athletes receive the best training their countries can offer, it’s superior physiology that determines who the top three athletes are in the world.

Does that mean athletes blessed with less-than-perfect genetics should give up? Absolutely not. Many athletic events and sports demand more than just the right muscles. Tactical and technical skill are necessary in many sports and can trump pure physiology. But Rassier believes that even in sports like soccer and tennis, the top athletes benefit from having a muscle-fibre makeup uniquely suited to their sport.

What’s important to note in all of this is that at lower levels of competition, the perfect set of muscles play less of a role. At that level, training, coaching, experience, dedication and the mental aspect of sport are a larger factor in athletic success.

Also worthy of note is that with the right training, muscle fibres are amenable to change. Extensive endurance training can convert a percentage of fast twitch to slow-twitch fibres. However, Rassier cautions that no amount of training will make sprinter Usain Bolt into the next Olympic marathoner.

The transition from slow twitch to fast twitch is far less successful. Therefore it’s also unlikely that marathoner Paula Radcliffe will vie for a spot on the British women’s 4x100 relay.

Rassier says something as simple as a muscle biopsy can determine who has the genetics to be among the top athletes in the world. And he believes there’s a case for using biopsies as a screening tool to determine the genetic potential of world class athletes.

“They should be aware of their potential before deciding to dedicate decades of their life trying to win an Olympic medal,” Rassier said.

The same can be said for sporting organizations that are dedicating thousands of dollars worth of resources trying to develop Olympic champions. Understanding the genetic limits of their athletes can help apply resources accordingly.

Rassier is certain that some countries are already doing this type of athlete screening though there is little acknowledgement of such practices.

Once again Rassier cautions that this doesn’t mean young athletes can’t choose their own sport or that they should feel limited in their ability to excel. In fact, he’s not sure when during a young developing athlete’s career a muscle biopsy will yield the kind of information needed to determine their athletic potential.

What he is sure about is that the majority of young athletes will never have to fall back on genetics alone to find success at most levels of competitive sport. That said, he’s convinced that the majority of young athletes naturally gravitate to the sport in which they are most genetically gifted.

Finally, it’s worth noting that the predominance of any one muscle fibre type is specific to the individual muscle, which means you can have a high proportion of fast-twitch fibres in one muscle and not another. In other words, you can bet your next paycheque that the calves and thighs of Usain Bolt are teeming with more fast-twitch fibres than the rest of his competition.

Comments

We encourage all readers to share their views on our articles and blog posts. We are committed to maintaining a lively but civil forum for discussion, so we ask you to avoid personal attacks, and please keep your comments relevant and respectful. If you encounter a comment that is abusive, click the "X" in the upper right corner of the comment box to report spam or abuse. We are using Facebook commenting. Visit our FAQ page for more information.

Almost Done!

Postmedia wants to improve your reading experience as well as share the best deals and promotions from our advertisers with you. The information below will be used to optimize the content and make ads across the network more relevant to you. You can always change the information you share with us by editing your profile.

By clicking "Create Account", I hearby grant permission to Postmedia to use my account information to create my account.

I also accept and agree to be bound by Postmedia's Terms and Conditions with respect to my use of the Site and I have read and understand Postmedia's Privacy Statement. I consent to the collection, use, maintenance, and disclosure of my information in accordance with the Postmedia's Privacy Policy.

Postmedia wants to improve your reading experience as well as share the best deals and promotions from our advertisers with you. The information below will be used to optimize the content and make ads across the network more relevant to you. You can always change the information you share with us by editing your profile.

By clicking "Create Account", I hearby grant permission to Postmedia to use my account information to create my account.

I also accept and agree to be bound by Postmedia's Terms and Conditions with respect to my use of the Site and I have read and understand Postmedia's Privacy Statement. I consent to the collection, use, maintenance, and disclosure of my information in accordance with the Postmedia's Privacy Policy.